The present invention relates to a device and method for reshaping a corneal surface of an eye for refractive correction by laser ablation, and more particularly to a device and method for simulating the reshaping of the corneal surface.
Various lasers have been employed for ophthalmic surgery applications including the treatment of various eye disorders such as glaucoma, cataract, myopia, hyperopia, and astigmatism. In order to correct some of these eye disorders a laser is used to ablate or remove a portion of the corneal surface of an eye in order to reshape the cornea. Typically, such laser refractive surgery is achieved through a plurality of ablated layers, the cumulative affect of the plurality of ablated layers attempting to remove a portion of the cornea to reshape the cornea to correct the curvature of the eye. However, before attempting laser surgery on the cornea, most laser systems in use require the ophthalmologist to practice the ablation on a piece of plastic or metal. Once the practice piece is completed it is necessary to estimate the corresponding depth of ablation in the cornea by using one or more conversion factors. Such conversions or estimates are only approximations and do not completely and accurately determine the depth of ablation. In some situations such estimates are no more than an educated guess that the ablation profile performed on the practice piece will correct an eye disorder in an actual human eye. Additionally, in one available system, the EXCALIBER manufactured by LaserSight Technologies, a visual profile of the ablated cornea is created. However, with the EXCALIBER, a test ablation is still performed on a plastic sample and the profile is created through estimated conversion factors.
It would be advantageous if a simulated ablation profile of a cornea could be constructed or generated without the use of a practice or test piece of synthetic material. The present invention is designed to obviate and overcome many of the disadvantages and shortcomings experienced with the use of a practice piece of material. The present invention eliminates the test ablation on a synthetic material and a computer is used to directly translate actual laser energy pulses into a three dimensional view of corneal stroma ablation. In this manner, the present invention simulates ophthalmic surgery for correcting a disorder of an eye without actually performing surgery on an eye.